Suppose that the good professor had instead taken a randomized and enumerated list of all students in the UC system and randomly selected a starting point on that list (say, student number 21,058). He then selects that student for inclusion in the sample, and every 25th student thereafter (cycling back through students 1-21,057). What sampling design did he use

Systematic sampling

Step-by-step explanation:

Here , Professor had taken a randomized and enumerated list of all students in the UC system and randomly selected a starting point on that list.

He then selects that student for inclusion in the sample, and every 25th student thereafter.

That clearly shows that he is following the systematic sampling technique, where k= 25.

Hence, the sampling design he used = systematic sampling

10              4     ,  so basically you cross multiply : 10x=20 20 divided by 10 is 2 . x=2

___   =        ___

5               x